I. Field of the Invention
This invention relates to locks for securing an insert mating received within a sleeve of a vehicle hitch and, in particular, to a coupler lock with ease of operation by manually engaging a lock assembly to capture a plurality of ball bearings within an annular groove of a lock bar to prevent separation of the lock housing from the lock bar thereby securing the insert within the hitch sleeve.
II. Description of the Prior Art
Historically, hitches mounted to a towing vehicle included fixed components permanently secured to the vehicle. The hitch body was bolted or welded to the vehicle and included a hitch ball fixed to the hitch structure. As hitch manufacturers developed more uses for their hitches, the fixed ball was replaced by a removable ball insert received within a sleeve forming a part of the hitch body. Both the insert and sleeve had a rectangular configuration such that the sleeve would matingly receive the insert. To prevent inadvertent removal of the sleeve, a pin inserted transversely through the insert and sleeve mated the components. The insert could be conveniently removed for interchange to a different insert associated with an accessory such as a cargo platform, bike carrier, ski rack, etc. However, this freedom to interchange accessories also lended them to theft since removal was as simple as removing a pin.
In order to prevent removal of the lock pin and therefore unauthorized removal of the hitch accessory, various locking means were developed. A lock secured to the pin was first developed which prevented withdrawal of the pin without first removing the lock. These add-on locks proved cumbersome to use and were subjected to the elements of the road along with the rest of the undercarriage.
Specialized lock pins incorporating a locking mechanism were developed which allowed the user to replace the lock pin with the coupler lock. These locks included a combination or key lock to release the coupler lock for removal of the insert. However, many of these coupler. locks were inconvenient to use and subject to failure because of the locking mechanisms.
The present invention overcomes the disadvantages of the prior known coupler locks by providing a convenient to use lock which can be engaged with a push of a button to engage ball bearings to capture a locking pin of the lock.
The coupler lock of the present invention has a barbell configuration with enlarged end portions and a narrower intermediate section configured to fit through the aligned apertures of the hitch sleeve and the insert. One of the enlarged ends is a lock housing which is detachable from the lock pin upon operation of the key lock. The lock pink may be inserted through the sleeve and insert and the lock housing attached to the free end of the lock pin to secure the coupler lock in the hitch.
The lock housing includes radially movable ball bearings adapted to selectively engage an annular groove in the end of the lock pin. The ball bearings are forced radially inward into the groove of the lock pin by a locking cup which is longitudinally shiftable within the lock housing. The locking cup is biased toward an unlocked position by a spring and moved to the locked position upon engagement of the lock cylinder. The lock cylinder is manually shiftable to force the locking cup over the bearings. A key must be used to release the lock allowing the locking cup to be longitudinally biased by the spring to release the ball bearings. The primary advantage of the present invention is the convenience of manually locking the lock simply by depressing the lock cylinder.
Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings.